Stress Response of Mouse Embryonic Fibroblasts Exposed to Polystyrene Nanoplastics

Abstract

Polystyrene (PS) nanoplastic exposure has been shown to affect the viability of neuronal cells isolated from mouse embryonic brains. However, the viability of mouse embryonic fibroblasts (MEFs) was not affected although PS nanoplastics accumulated in the cytoplasm. It is currently unknown whether MEFs do not respond to PS nanoplastics or their cellular functions are altered without compromising viability. Here, we found that PS nanoplastics entered the cells via endocytosis and were then released into the cytoplasm, probably by endosomal escape, or otherwise remained in the endosome. Oxidative and inflammatory stress caused by intracellular PS nanoplastics induced the antioxidant response pathway and activated the autophagic pathway. However, colocalization of the autophagic marker LC3B and PS nanoplastics suggested that PS nanoplastics in the cytoplasm might interfere with normal autophagic function. Furthermore, autophagic flux could be impaired, probably due to accumulation of PS nanoplastic-containing lysosomes or autolysosomes. Intriguingly, the level of accumulated PS nanoplastics decreased during prolonged culture when MEFs were no longer exposed to PS nanoplastics. These results indicate that accumulated PS nanoplastics are removed or exported out of the cells. Therefore, PS nanoplastics in the cytoplasm affect cellular functions, but it is temporal and MEFs can overcome the stress caused by PS nanoplastic exposure.

Nanomechanical Atomic Force Microscopy to Probe Cellular Microplastics Uptake and Distribution

“…Conversely, 100 nm particles even stimulated cell viability to 121.5 ± 6.9% at 10 µg/mL. These results correlate well with a recent study where mouse embryonic fibroblasts were subjected to 100 nm polystyrene beads, which also did not affect the viability and proliferation of the cells [ 32 ]. However, other polystyrene beads of other sizes were not investigated using fibroblasts cell cultures, therefore we indicate here that the size-dependent effects are likely and need to be studied in more detail in the future.…”

PS-NPs Induced Neurotoxic Effects in SHSY-5Y Cells via Autophagy Activation and Mitochondrial Dysfunction

“…The data of Nie et al indicated the upregulation of Atg7, Atg5, and LC3-II protein expression and the fluorescence intensity of GFP-LC3 in SH-SY5Y cells after exposure to 60 nm PS-NPs [ 34 ]. Exposure to 100 nm PS-NPs could increase LC3 autophagic pathway activation in mouse embryonic fibroblasts (MEFs) [ 58 ].…”

Microplastics and Nano-Plastics: From Initiation to Termination

“…While it is unknown if these compounds leak straight into living tissues, some additives like Bisphenol A have been discovered to be consumed by marine biota (Chen et al, 2020;Koelmans et al, 2014), Absorption of this leachate frequently used in lining food and beverage cans, can induce endocrine problems and adversely affect human health (Ryan, 2015). In particular, associated health risks may include, cytotoxicity (Gopinath et al, 2021), neurotoxicity (Han et al, 2021;Varsou et al, 2021), immunotoxicity, reproductive toxicity (He et al, 2021), or even carcinogenicity (Gao et al, 2021). Yip et al (2022) have tested and predicted the possibility of MNPs transfer from mother to offspring.…”